Can confirm the ssocc 0.5 coils are 316l. The ssocc 1.2 and 1.5 are nickel.
https://kangeronline.com/products/kanger-stainless-steel-organic-cotton-coil?variant=9185586373
So all ssocc 0.5 coils available I'm the UK should all know be 316L wire. The occ are nickel. I do remember now when the first ssocc coils came out they where a small barrel shape with two juice inlets. These only ran for a month before being replaced with the bigger 3 hole (1small, 2 large) barrel shape steel wire coils.
Long and short is you shouldn't find anything but steel wire ones that are capable of tc or wattage in the uk under the ssocc logo.
The big plus is every vape shop has them and you have tons of choice from 0.2 to 1.5 and clapton, ceramic ect ect.